Revolutionary New Way of Astronomical Observation: Radio Astronomy, 1932.

JF Ptak Science Books Post 1395

"At the age of just twenty-six, Karl Jansky had become the first person to detect and identify radio waves coming from outer space, a truly historic discovery... The true significance of Jansky's breakthrough surpasses even the momentous discovery that the Milky Way emits radio waves. His accomplishment was to establish the science of radio astronomy and to demonstrate that astronomers could learn a huge amount about the universe by looking beyond the narrow band of electromagnetic wavelengths that are visible to the human eye... He announced his result in a paper entitled 'Electrical Disturbances Apparently of Extraterrestrial Origin' --Simon Singh, The Big Bang.

"In conclusion, data have been presented which show the existence of elctromagnetic waves in the Earth's atmosphere which apparently come from a direction that is fixed in space." Karl Jansky, (1932), page 1398.

Found in these three papers (below) is the description of the discovery of an entirely new astronomy, a brand new way of looking at the universe. Instead of using telescopes operating at optical wavelength of about 10-5 cm and gathering information visible to the eye, Karl Jansky used a technology that had previously been employed in transoceanic communication. It was in the communication field that Jansky was working (for Bell Labs), trying to identify an interfering hiss, in which he came to realize (and displayed in this series of papers) that this long radio wavelength interference was something extraordinary, publishing his first results in 1932.1 It was later in 1933 that he published his findings that this "hiss" was not "local", and the serendipitous discovery came from a source outside our solar system, which was a tremendously significant finding2, "his revolutionary claim that the hiss static seemed to have its origin in our Milky Way galaxy, with a maximum in a direction that pointed close to the galactic center" (American National Biography). His third paper of 19373 discusses further problems of interference in the short-wave systems. (These three papers are offered for sale at our blog bookstore, here.)

But it wasn't so significant to most of the rest of the astronomy world, because, well, no one rushed out to replicate his findings. At least no one until Grote Reber, who (necessarily) built his own equipment (a 9m parabolic radio telescope ) and set up shop in his backyard around 1937, publishing his results and confirming Jansky's efforts in the Astrophysical Journal in 1944. Also it should be noted that J.S. Hey (a British Army officer) detected radio waves emitted from the sun for the first tome on 27 February 1942.

Jansky was interested in pursuing this work in astronomy, but Bell Labs took him away from this area, giving him other assignments, leaving the rest of the new world of radio astronomy for others to operate in. Subsequently, radio sources were found in stars and galaxies, and were emitted from entirely new classes of objects like quasars, pulsars and radio galaxies. And in fact the discovery of the cosmic microwave background radiation which came through a series of surprises to Penzias and Wilson and which offered compelling evidence in support of the Big Bang (the background radiation of which had earlier been theorized by Gamow and Alpher and Wilson but which was evidently not known to P+W and therefore not referenced), was made in a similar way, via sweet serendipity, while the pair was working on something else for Bell Labs.

Karl Guthe Jansky, born 22 October 1905, died of a heart condition at age 44, 22 October 1950.

Notes:

1) "Directional Studies of Atmospherics at High Frequencies." In: Proceedings of the Institute of Radio Engineers, vol.20, no.12 (Dec.1932), pp.1920-1932.

In fact Nickola Tesla and Oliver Lodge had previously attempted to detect radio emissions coming from the sun, but both failed, mainly due to the inhibitions of their equipment.

All published in the Proceedings of the Institute of Radio Engineers, Menasha, Wisconsin. : Institute of Radio Engineers, the three papers published 1932-1937. All in their original printed wrappers. Very nice copies. Very scarce.

See also: Lang and Gingerich, A Source Book in Astronomy and Astrophysics, 1900-1975, Harvard, 1979, pp 30-31, paper #6. (The authors use Jansky's paper of 1935, "A Note on the Source of Interstellar Interference", published in the Proceedings of the IRE as the chief paper, though noting that the 1932 paper was the "first report on these studies". In this 1935 paper Jansky of course references his "former papers" (our #s 1+2 above).